Kozak left Lazio on transfer deadline day.
"He is an inspiration to me and someone I look up to," the Czech Republic international to avfc.com.
"He was one of the best strikers in the world - maybe not right now but a few years ago.
"I was able to play and train with him and see him up close.
"Off the pitch we played tennis together a lot as it is a sport we both enjoy. He always won - he was very strong!
"I wasn't so strong but I beat him maybe once! But off the pitch he is a quiet man and a very good person."
For breaking stories and all the great banter like us on Facebook: facebook.com/tribalfootball